Question 1203735: The sum of Jess, Sam and Mindy’s ages is 42. Jess is younger than Sam, but older than Mindy. Sam
is twice as old as Mindy, who is the youngest out of the three by 6 years. If Jess is 15 years old, how
old are Sam and Mindy?
Found 4 solutions by ikleyn, greenestamps, josgarithmetic, MathTherapy:
Answer by ikleyn(52794)   (Show Source):
You can put this solution on YOUR website! .
The sum of Jess, Sam and Mindy’s ages is 42. Jess is younger than Sam, but older than Mindy. Sam
is twice as old as Mindy, who is the youngest out of the three by 6 years. If Jess is 15 years old, how
old are Sam and Mindy?
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Could you clarify please the meaning of this sentence
"Sam is twice as old as Mindy, who is the youngest out of the three by 6 years. "
As written, this sentence is grammatically absurdist and contradicts to the rest
of the given information, making the entire problem non-sensical.
If you read this problem in class, then many students will be shocked, and some may feel bad.
Answer by greenestamps(13200)  (Show Source):
You can put this solution on YOUR website!
The given fact that the sum of their ages is not needed; the problem can be solved with the other information.
Jess is 15.
Jess is younger than Sam and older than Mindy.
Mindy is the youngest, by 6 years, so Mindy is 15-6 = 9.
Sam is twice as old as Mindy, so he is 9*2 = 18.
Yes, the sum of their ages is 15+9+18 = 42 -- but we didn't need that information to solve the problem.
ANSWER: Mindy is 9, Sam is 18
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Note the solution from tutor @josgarithmetic uses an equation that says Mindy is 6 years younger than Sam, which is not correct, leading of course to a wrong solution. The tutor should have realized the solution was wrong, since the sum of the ages he ended up with is not 42.
Answer by josgarithmetic(39618)  (Show Source):
Answer by MathTherapy(10552)  (Show Source):
You can put this solution on YOUR website!
The sum of Jess, Sam and Mindy’s ages is 42. Jess is younger than Sam, but older than Mindy. Sam
is twice as old as Mindy, who is the youngest out of the three by 6 years. If Jess is 15 years old, how
old are Sam and Mindy
Jess: J
Sam: S
Mindy: M
Jess is younger than Sam, so: J < S
Jess in older than Mindy, so: J > M
Sam is twice Mindy's age, so S = 2M ----- eq (i)
Mindy is the youngest of the 3 by 6 years. Because Jess is the 2nd youngest, Jess is 6 years older than Mindy.
Hence, J = M + 6 ----- eq (ii)
15 = M + 6 ---- Substituting 15 (given) for Jess, in eq (ii)
15 - 6 = M
9 = M (Mindy's age)
S = 2(9) ------ Substituting 9 for M in eq (i)
Sam's age, or S = 18
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